----- Original Message -----
From: "Chris Brogden" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: February 16, 2001 9:48 PM
Subject: Re: Fast film to go with Porta 160
> On Fri, 16 Feb 2001, William Robb wrote:
>
> > I am saying that C-41 film does not push. Period. That's
sure
> > simple.<G>
> > William Robb
>
> Ok, I'll stay simple, too (not hard for me to do on a Friday,
believe
> me). :) Last week I shot a roll of 800 speed film at 1600
and had it
> developed as though it were a 1600 speed film. I say that I
pushed
> it. What definition of "push" are you using? When you say
"push," what
> process or result are you talking about? I'm using it purely
to mean
> developing a film as though it were faster than it really is,
which
> obviously can be done. What does pushing do to black and
white film that
> it doesn't to colour?
Traditionally, "pushing" means to deliberately underexpose an
emulsion, then attempt to get lost detail back by using longer
than standard developing times. This is the definition I use,
anyway.
Since all C-41 films (I will presime C-41 since that what I
started with at the beginning of the topic, if you are changing
the subject, then please tell me) are processed for the same
time, temperature, agitation scheme, I would say what you dis
was underexpose by a stop. In C-41, 800 and 1600 have the same
processing time.
See:
http://www.accesscomm.ca/users/wrobb/FilmTests/PJ800/PJ800.html
for a look at what happens to a C-41 film when "pushed". My
understanding and experience has been that C-41 is a develop to
completion process, unlike E-6 and black and white, and that the
films resist attempts to invrease the speed. Personally, I don't
think it is possible to actually increase the speed of a
negative film via development strategies.
If film is exposed within it's latitude (which means the scene
must fall within the dynamic range of the emulsion), then a
usable negative will result. If the exposure falls outside the
usable range of the emulsion, then a compromised negative
quality will result, no matter what development strategy is used
to try to save the film.
I have heard that it is in fact possible to push process E-6
films, though I have no first hand experience.
William Robb
>
> chris
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